This invention relates to suspension assemblies for vehicles, and more particularly, the invention relates to suspension assemblies for changing the camber of a wheel during vehicle ride conditions.
A particular suspension assembly defines a suspension parameter such as caster, camber, and toe. It is often desirable to change these parameters during vehicle ride conditions such as vehicle roll. For example, it is desirable to change vehicle camber during vehicle roll conditions to provide better control over the vehicle. To this end, suspension assembly arrangements are utilized which incorporate a short upper arm and a long lower arm for supporting the knuckle. As the wheel moves up and down during vehicle roll conditions, the geometry of these suspension assemblies changes the wheel camber to provide better control of the vehicle. However, suspension assemblies incorporating upper and lower control arms are difficult to package in a vehicle and cannot be incorporated as often as desired. Instead, MacPherson or Chapman struts are often utilized, which do not permit the camber to change during vehicle roll conditions since the upper attachment or mount of the strut is fixed to the vehicle frame.
Suspension assemblies incorporating adjustable struts have been proposed to permit the wheel camber to be changed in response to vehicle roll conditions. In the prior art, the position of the upper strut mount is shifted laterally to change the wheel camber. The prior art suspension assemblies incorporate a sensor for sensing the steer angle, a controller for processing the information from the sensor, and an actuator for laterally shifting the upper strut mount. However, these active control systems may be costly in that a sensor and controller are required to precisely actuate the actuator. Therefore, what is needed is a simplified suspension assembly incorporating a strut, which changes the wheel camber in response to vehicle roll conditions.
The present invention provides a suspension assembly for a vehicle including a frame. A lower control arm having first and second opposing portions is pivotally connected to the frame at the first portion. A knuckle is supported on the second portion of the lower control arm with a wheel supported on the knuckle. A strut having a lower end is connected to the knuckle and an upper end of the strut is connected to the frame at an upper connection. The upper connection generally constrains the upper end of the strut against vertical movement while permitting limited lateral movement of the upper end relative to the frame. In one embodiment, a linkage assembly including a first linkage portion is interconnected between the lower control arm and the frame. A second linkage portion interconnects the upper end of the strut and the first linkage portion for moving the upper end laterally in the upper connection in response to vertical movement of the lower control arm. In a second embodiment, an adjustable linkage assembly including a first adjustable linkage is interconnected between the upper end and the frame. A second adjustable linkage is interconnected between the lower control arm and the frame and changes length in response to vertical movement of the lower control arm. A link interconnects the first and second adjustable linkages for communicating the change in length of the second adjustable linkage to the front adjustable linkage for moving the upper end laterally in the upper connection in response to vertical movement of the lower control arm.
Accordingly, the above invention provides a simplified suspension assembly incorporating a strut, which changes the wheel camber in response to vehicle roll conditions.